$ {{-5}\cdot \left[ \begin{array}{cc} -8 \\ 4 \\ -4 \end{array} \right]=}$
The Strategy To multiply a matrix by a scalar, we multiply each term of the matrix by the scalar. Multiplying each term $ {\begin{aligned}-5\cdot \left[\begin{array}{rr} {-8} \\ {4} \\ {-4} \end{array}\right]&=\left[\begin{array}{rr} -5\cdot{-8} \\ -5\cdot{4} \\ -5\cdot{-4} \end{array}\right] \\\\&=\left[\begin{array}{rr} {40} \\ {-20} \\ {20} \end{array}\right]\end{aligned}}$ Summary $ {{-5}\cdot \left[ \begin{array}{cc} -8 \\ 4 \\ -4 \end{array} \right]=\left[ \begin{array}{cc} 40 \\ -20 \\ 20 \end{array} \right]}$